I need your advice as I don't know if I hit a bug, or I am misunderstanding something. On a Debian Lenny, I am trying to prevent the installation of two particular packages, when they are requested as dependencies fromother packages. I am using the same syntax I successfully used in Squeeze, but with no success at all. On squeeze, the following works as expected: # cat /etc/apt/preferences.d/local-no-pike.pref Package: pike7.6-core Pin: version * Pin-Priority: -1000 If I try to install pike7.6, which depends on pike7.6-core, apt and aptitude refuse to do so. On Lenny, the only difference is that there is no support for "fragments" in /etc/apt/preferences.d, and all preferences must be in the /etc/apt/preferences file. But it's not working. E.g., if the file contains: Package: grub-common Pin: version * Pin-Priority: -1000 apt doesn't stop me from installing grub, which depends on grub-common. I used strace to see if the file is being read, and it is. I was suggested to use some Debug:: options, but they didn't help to pinpoint the problem either. I have google'd a lot with some combinations of "lenny" "prevent" "package" "installation" "pinning" and the like, but nothing nice came out. And of course I read man apt_preferences. What am I missing here?